When are DNS records synced to a cluster?

Hi,
I setup a nameserver cluster for my servers but I'm confused to when each server syncs their dns records to the cluster of nameservers?
I edited a DNS record on a server and assumed the changes would immediately be copied to the nameservers but it wasn't.

DNS zone should be synced without delay but you may need to check the bind reload setting at
Main >> Server Configuration >> Tweak Settings
Also verify that named is reloading fine on your server and clusters.